This invention relates to electrical contacts for an electrical connector and a method of making the contacts. More specifically, this invention relates to electrical contacts of the type wherein a plurality of fine wires are held together and axially-aligned in a bundle within a sleeve and the wires provide surfaces for mating and electrical conductivity with a second contact in another connector. The second contact may be either a similar contact or one of a plurality of conventional but dissimilar contacts.
Electrical contacts of the type including a plurality of axially-aligned fine wires held in a sleeve are old and known in the prior art, as evidenced by the Brush Contact Patent. Such a contact typically includes a plurality of wires, each with acutely angled forward end portions and held within a holder simply by a crimp of the holder radially inwardly providing a frictional retention among the wires and between the holder and the plurality of wires.
The manufacture of electrical connectors of the type described in the Brush Contact Patent is not the ultimate in simplicity or cost effectiveness. The manufacturing requires that the individual wires be separately made, handled, and channeled into a sleeve which is only fractionally larger internally. Channeling the wires into such a sleeve may damage the wires in some instances.
The crimping operation in the manufacture of the prior art electrical connector is necessary to securely hold all of the wires together and within the sleeve. This presents an undesirable feature of requiring an undesirably high force to secure all the wires within the sleeve.
The electrical resistance of the prior art contact depends partially on the quality of the crimp, so a poor crimp can significantly increase the electrical resistance of the contact. Since a low resistance in a contact is necessary, particular care (with resulting expense) was directed to obtaining a good crimp.
In some instances it is desirable to verify that the correct number of wires (perhaps within a small tolerance) is included in the plurality of wires. In the prior art methods of making such a contact, a mechanical way of determining assembly with the wires in the comparatively heavy sleeve against a nominal weight. The heavy sleeve makes it difficult to determine the exact number of wires included. The number of wires is important to the retention of wires within the sleeve and to the electrical resistance of the bundle in prior art applications.
Electrical contacts including a welded end are not themselves new. One such contact including a welded end is shown in a prior art patent (Re 25,798) to Platz et al for "Plug-In Connector". Such a contact was formed to have a relatively high mating force which is undesirable and a relatively high manufacturing cost.
The foregoing and other limitations of the prior art present problems in the manufacturing of the contact and the subsequent reliability of such a contact.